The main objective of the Biological Measures Core is to provide technical support for the biological measures that are necessary for the research projects in the Center. There are three classes of biological measures that will be supported by this Core: psychophysiological methods, hormonal assays, and imaging. The imaging component will include both MRI (for Projects 1, 4, and 5) and microPET (for the non-human primate project, Project 1). The neuroimaging portion of the Core will be responsible for maintaining imaging protocols, performing regular evaluations of imaging scanner performance and image data quality, evaluating new methods for data acquisition,and analysis, and managing a database of imaging, hormonal, behavioral, psychophysiological, and clinical measures obtained by the project. Hormonal assays include salivary and blood cortisol, DHEA and testosterone, and CRF and ACTH. Psychophsysiologic measures include EEG, emotion-modulated startle and cardiovascular measures.